Malawi's President Peter Mutharika and the country's electoral commission have formally filed an appeal against a court ruling that overturned his win last year.

"I can confirm that the court has received both appeals by first respondent [the president] and second respondent [electoral commission]," High Court Registrar Agnes Patemba told the Reuters news agency on Friday.

A sworn statement by Malawi Electoral Commission (MEC) Chairperson Jane Ansah, who supports the appeal, said the constitutional court overstepped its powers by ordering parliament to convene within 21 days to amend the Electoral Act.

Ansah's statement also asserts that the budget for a fresh election would cost Malawi a lot of money unless enforcement of the court's judgement is suspended.

The constitutional court on Monday annulled last year's disputed presidential election results, citing "widespread" irregularities and ordering a new vote.

The election last May returned the sitting president to power, leading to deadly confrontations and widespread unrest.

The MEC had declared Mutharika the narrow winner of the May election with 38 percent of votes, followed by Lazarus Chakwera with 35 percent and former Vice President Saulos Chilima third with 20 percent.

Mutharika had denounced the ruling as "a serious subversion of justice, an attack on our democratic systems and an attempt to undermine the will of the people".